This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Hamamatsu Photonics has developed a prototype dual channel time domain tissue oximeter. Hamamatsu is currently searching for applications for which this device may be used. Tests of instrument signal-to-noise, stability, user and patient interfaces, and overall system performance will be assessed.